Merc Exhaust question

[RomanRegal]

Hi, I just recently replaced the maniolfds and risers on my 1987 350S/B 260 HP. The risers are 4". The exhaust pipe that connects to the riser with a rubber bellows has a 4 inch opening and the narrows to three inches the rest of it legnth Is there going to be too pressure from the 4:inch riser into the three inch exhaust pipe.<br />Thanks again Roman

 

[Haut Medoc]

Re: Merc Exhaust question

Do you mean excessive back pressure? I doubt it.

 

[QC]

Re: Merc Exhaust question

I second the doubt. Does this have thru-transom or thru-prop exhaust? Are the neck down and three inch exhaust the same setup as before you swapped out the risers?

 

[RomanRegal]

Re: Merc Exhaust question

The exhaust is thru prop. The old riser was a three inch and the neck down and pipes are the same as before. My concern was for back pressure?<br />Thanks again. Roman

 

[QC]

Re: Merc Exhaust question

My thought is that you have not changed the minimum diameter, only moved it. I say, non-issue.